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Browsing by Author "Sun, Yu"

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    Factors influencing high respiratory mortality in coal-mining counties: a repeated cross-sectional study
    Shi, Ruoding; Meacham, Susan; Davis, George C.; You, Wen; Sun, Yu; Goessl, Cody (2019-11-08)
    Background Previous studies have associated elevated mortality risk in central Appalachia with coal-mining activities, but few have explored how different non-coal factors influence the association within each county. Consequently, there is a knowledge gap in identifying effective ways to address health disparities in coal-mining counties. To specifically address this knowledge gap, this study estimated the effect of living in a coal-mining county on non-malignant respiratory diseases (NMRD) mortality, and defined this as “coal-county effect.” We also investigated what factors may accentuate or attenuate the coal-county effect. Methods An ecological epidemiology protocol was designed to observe the characteristics of three populations and to identify the effects of coal-mining on community health. Records for seven coal-mining counties (n = 19,692) were obtained with approvals from the Virginia Department of Health Office of Vital Statistics for the years 2005 to 2012. Also requested were records from three adjacent coal counties (n = 10,425) to provide a geographic comparison. For a baseline comparison, records were requested for eleven tobacco-producing counties (n = 27,800). We analyzed the association of 57,917 individual mortality records in Virginia with coal-mining county residency, county-level socioeconomic status, health access, behavioral risk factors, and coal production. The development of a two-level hierarchical model allowed the coal-county effect to vary by county-level characteristics. Wald tests detected sets of significant factors explaining the variation of impacts across counties. Furthermore, to illustrate how the model estimations help explain health disparities, two coal-mining county case studies were presented. Results The main result revealed that coal-mining county residency increased the probability of dying from NMRD. The coal-county effect was accentuated by surface coal mining, high smoking rates, decreasing health insurance coverage, and a shortage of doctors. In Virginia coal-mining regions, the average coal-county effect increased by 147% (p-value< 0.01) when one doctor per 1000 left, and the effect increased by 68% (p-value< 0.01) with a 1% reduction of health insurance rates, holding other factors fixed. Conclusions This study showed a high mortality risk of NMRD associated with residents living in Virginia coal-mining counties. Our results also revealed the critical role of health access in reducing health disparities related to coal exposure.
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    Investigation of Causes and Evaluation of Programs: three applications of Health Economics
    Sun, Yu (Virginia Tech, 2017-06-22)
    In chapter 1, a comprehensive meta-analysis is conducted to synthesize the effectiveness, cost, and cost-effectiveness of lifestyle diabetes prevention interventions and compare effects by intervention delivery agent and channel. Sixty-nine studies meet inclusion criteria. The results show that participants receiving intervention with nutrition education experienced a reduction of 2.07 kg (95% CI: 1.52 to 2.62; p<0.001; 95% CI: 88.61% to 92.87%) in weight at 12 months with effect sizes over time ranging from small (0.17, 95% CI: 0.04 to 0.30; p=0.012; 95% CI: 80.42% to 91.14%) to medium (0.65, 95% CI: 0.49 to 0.82; p<0.001; 95% CI: 98.52% to 98.94). In sum, lifestyle interventions are effective in reducing body weight and glucose-related outcomes. Dietitian-delivered interventions achieve greater weight reduction compared to those delivered by other personnel. In chapter 2, this study attempts to examine the effects of household relative deprivation on children's health outcomes. A modified household production model is developed with energy intake, energy expenditure and a composite good as main inputs in the health production. A two-stage Stackelberg game facilitates the need to model the parent-child interaction which follows similar structure as You and Davis (2011). We use three measurements of relative deprivation based on per capita household income and four reference groups based on combinations of geographic and demographic characteristics. The results show that relative deprivation is negatively associated with child health. In chapter 3, we define "process benefits" as the direct effect on utility from engaging in an activity and examine how "process benefits" associated with food activities, both uptake and duration, are related to factors such as socio-economic status and demographics. A household production model is utilized to demonstrate the vital role of process benefits in home food production and the implications it will have for nutrition based policies targeting resources. The results display that the process benefits are associated with some demographic characteristics. This implies that shortfalls in food activities are not simply a matter of technology or resource shortfalls, but also reflect disutility associated from these activities which in turn will attenuate the impact of policies design to merely address resource shortfalls.